Bulgarian National Bank Exchange Rates API — bnb-exchange-rate

Official Bulgarian National Bank (Bulgaria) daily exchange rates for Node.js and TypeScript. The published central bank rates behind tax filings, customs valuations, audits, and compliant invoicing — not market estimates, but the numbers Bulgarian National Bank itself prints, every business day.

🚀 Why this client?

• 🏛️ Official published rates — Bulgarian National Bank's own table, with the publisher's own rate_date on every response
• 📅 History back to 2016 — point-in-time tables and daily series for any past date
• 🔀 Published vs derived, always flagged — computed inverse/cross pairs carry derived: true, never mixed with official prints
• ⚡ Zero dependencies — pure ESM + CJS over global fetch; Node 18+, Bun, Deno, and edge runtimes
• 🔷 Type-safe — full TypeScript definitions shipped with the package
• 🧾 Compliance-grade metadata — rate_type, publication date, and source disclaimer on every response

Official rate, not mid-market: every value here is a number Bulgarian National Bank itself published, fixed once printed and carrying the central bank's own rate_date — what filings and audits require. Need the live interbank midpoint for pricing or display instead? Use the mid-market API or @allratestoday/sdk. The two can diverge by several percent.

⚡ Try it without a key

The latest Bulgarian National Bank table is also served keyless, CORS-open and edge-cached, for evaluation, embeds and AI agents:

curl "https://allratestoday.com/api/open/central-bank/bnb?source=EUR&target=USD"

const r = await fetch('https://allratestoday.com/api/open/central-bank/bnb').then((x) => x.json());
console.log(r.rate_date, r.rates.length); // the central bank's latest published table, no key

The open endpoint serves the latest table only and asks for a visible attribution link. The client below uses the keyed API, which adds point-in-time tables, history, and CSV/XML/Excel output.

🔑 Get your API key

Get a free API key at allratestoday.com/register — no credit card required. Latest rates are on every plan, including free.

📦 Installation

npm install bnb-exchange-rate

yarn add bnb-exchange-rate

pnpm add bnb-exchange-rate

Requires Node 18+ (global fetch); also runs on Bun, Deno and edge runtimes. Also published under the org scope as @allratestoday/bnb-exchange-rate — same code, same versions.

🏁 Quick start

import { getRate } from 'bnb-exchange-rate';

const pair = await getRate('EUR', 'USD', { apiKey: 'art_live_...' });
console.log(pair.rate, pair.rate_date); // the official Bulgarian National Bank rate, on the central bank's own date

📚 API reference

• Latest pair rate — one pair from the latest published table
• Full published table — everything the central bank printed, in one call
• Table for a date — the official table for an invoice or filing date
• Daily time series — one pair across a date range

Latest pair rate

Free plan and up. Pairs the central bank does not print directly are resolved from its table and flagged (see Published vs derived rates below).

const pair = await getRate('EUR', 'USD', { apiKey: 'art_live_...' });

Response:

{
  bank: 'bnb',
  name: 'Bulgarian National Bank',
  rate_date: '2026-09-09',   // Bulgarian National Bank's own publication date
  source: 'EUR',
  target: 'USD',
  rate: 1.1652,
  rate_type: 'reference',
  derived: false,
  method: 'published',
  disclaimer: 'Official rates as published by the named central bank. On weekends/holidays the most recent published rate_date is returned.'
}

Full published table

Free plan and up. The complete table for the latest publication date.

import { getLatestRates } from 'bnb-exchange-rate';

const table = await getLatestRates({ apiKey: 'art_live_...' });
console.log(table.rate_date, table.rates.length);

Response:

{
  bank: 'bnb',
  name: 'Bulgarian National Bank',
  rate_date: '2026-09-09',
  rates: [
    { "base": "EUR", "quote": "USD", "type": "reference", "value": 1.1652 },
    // … the rest of the published table (29 currencies vs EUR)
  ],
  disclaimer: '…'
}

Table for a date

Paid plans. The official table for any date since 2016 — weekends and holidays return the most recent published date, flagged via published_on_requested_date, which is exactly the in-force rate a filing needs.

import { getRatesForDate } from 'bnb-exchange-rate';

const day = await getRatesForDate('2026-06-30', { apiKey: 'art_live_...' });
// Optionally narrow to one pair:
const one = await getRatesForDate('2026-06-30', { apiKey: 'art_live_...', source: 'EUR', target: 'USD' });

Response:

{
  bank: 'bnb',
  requested_date: '2026-06-30',
  rate_date: '2026-06-30',                // the date actually published
  published_on_requested_date: true,      // false when a weekend/holiday fell back
  rates: [ /* the full table for that date */ ],
  disclaimer: '…'
}

Daily time series

Paid plans. One resolved rate per publication date — ready for charting, revaluation runs, or audit workpapers.

import { getHistory } from 'bnb-exchange-rate';

const series = await getHistory(
  { source: 'EUR', target: 'USD', from: '2026-01-01', to: '2026-09-09' },
  { apiKey: 'art_live_...' }
);

Response:

{
  bank: 'bnb',
  source: 'EUR',
  target: 'USD',
  from: '2026-01-01',
  to: '2026-09-09',
  count: 152,
  rates: [
    // one entry per publication date
    { date: '2026-09-09', rate: 1.1652, rate_type: 'reference', derived: false, method: 'published' },
    // …
  ],
  disclaimer: '…'
}

Pass { symbol: 'USD' } instead of source/target to get the raw published rows for one currency (all rate types, no pair resolution).

🗺️ Currencies covered

Bulgarian National Bank currently publishes rates covering 29 currencies against the EUR (as of the latest table):

🇦🇺 AUD · 🇧🇷 BRL · 🇨🇦 CAD · 🇨🇭 CHF · 🇨🇳 CNY · 🇨🇿 CZK · 🇩🇰 DKK · 🇬🇧 GBP · 🇭🇰 HKD · 🇭🇺 HUF · 🇮🇩 IDR · 🇮🇱 ILS · 🇮🇳 INR · 🇮🇸 ISK · 🇯🇵 JPY · 🇰🇷 KRW · 🇲🇽 MXN · 🇲🇾 MYR · 🇳🇴 NOK · 🇳🇿 NZD · 🇵🇭 PHP · 🇵🇱 PLN · 🇷🇴 RON · 🇸🇪 SEK · 🇸🇬 SGD · 🇹🇭 THB · 🇹🇷 TRY · 🇺🇸 USD · 🇿🇦 ZAR

🏛️ Source

The Bulgarian National Bank, founded in 1879, is one of the world's oldest central banks. Following Bulgaria's adoption of the euro, it publishes euro-denominated reference rates for around 30 currencies each business day.

• Publisher's own page: Exchange rates of foreign currencies · www.bnb.bg
• Publication: every business day; the exact schedule, freshness status and any current delay are on the Bulgarian National Bank rates page
• Values are stored unmodified, with the publisher's own rate_date on every row — see the methodology

🧭 Reading the numbers

• value is always quote currency per 1 unit of base currency (base: "EUR", quote: "USD", value: 1.15 means 1 EUR = 1.15 USD).
• Bulgarian National Bank quotes foreign currency per 1 EUR (e.g. base: "EUR", quote: "USD" means USD per one EUR).
• Need the other way round? Ask getRate(target, source) and the API inverts or crosses for you, flagged derived: true — never divide a published rate yourself in a compliance workflow.
• rate_type tells you which of the central bank's series a row belongs to (reference here); some publishers print buy/sell or several fixings for the same pair.

🧩 ERP & accounting systems

Loading the official Bulgarian National Bank rate into an accounting system is a supported workflow, not a hack. Step-by-step guides with the direction each system expects:

• Dynamics 365 Business Central — built-in Currency Exchange Rate Service, no code
• Xero · QuickBooks Online · SAP S/4HANA and ECC · Odoo

The same keyed endpoints return ?format=csv, ?format=xml and ?format=xlsx, and accept the key as ?api_key= on the URL for importers that cannot send headers:

curl "https://allratestoday.com/api/v1/central-bank/bnb/latest?format=xml&api_key=art_live_..."

🤖 AI agents

• MCP server: npx -y @allratestoday/central-bank-mcp (stdio) or the hosted endpoint https://allratestoday.com/api/mcp — tools for official rates, history, cross-bank comparison and publication calendars
• Machine-readable site guide: llms.txt · for-ai-agents

⚖️ Published vs derived rates

If Bulgarian National Bank does not print a pair directly, the API resolves it from the central bank's own table and says so — official and computed values are never confused:

| method | derived | Meaning | | --- | --- | --- | | published | false | The central bank printed this pair directly | | inverse | true | Computed as 1 ÷ the published opposite direction | | cross | true | Computed via EUR from two published rates |

🛡️ Error handling

Errors are thrown as Error with status (HTTP code) and body (the API's JSON error) attached:

try {
  const pair = await getRate('EUR', 'XXX', { apiKey: 'art_live_...' });
} catch (err) {
  console.log(err.message); // human-readable reason
  console.log(err.status);  // e.g. 404
}

| Status | Meaning | | ------ | ------- | | — | Missing apiKey (thrown before any request) | | 400 | Malformed date or parameters | | 401 | Invalid API key | | 403 | Endpoint needs a paid plan (historical dates & series) | | 404 | Pair or date range not covered by Bulgarian National Bank | | 429 | Monthly quota exceeded |

🔷 TypeScript

Full definitions ship with the package — no @types install:

import type { LatestRates, PairRate, DatedRates, RateEntry, HistoryQuery, RequestOptions } from 'bnb-exchange-rate';

📦 CommonJS

const { getRate } = require('bnb-exchange-rate');

getRate('EUR', 'USD', { apiKey: 'art_live_...' }).then((pair) => console.log(pair.rate));

💡 Quota tips

• Rates change once per business day — cache the published table locally and a small monthly quota goes a long way.
• Every request counts toward your AllRatesToday quota, shared across all AllRatesToday endpoints on your key.

📖 Methods reference

| Method | Plan | Description | | ------ | ---- | ----------- | | getRate(source, target, { apiKey }) | Free | Latest rate for one pair, resolved from the published table | | getLatestRates({ apiKey }) | Free | The central bank's full latest published table | | getRatesForDate(date, { apiKey, source?, target? }) | Paid | The official table (or one pair) for a YYYY-MM-DD date | | getHistory({ symbol \| source+target, from?, to? }, { apiKey }) | Paid | Daily series since 2016 |

📥 Bulk data (no key)

Need the whole archive rather than an API call? The same published tables are mirrored daily as open data:

• Hugging Face: AllRates/central-bank-exchange-rates — one CSV per institution (rates/bnb.csv)
• Kaggle: allratestoday/central-bank-exchange-rates
• CDN JSON: https://cdn.jsdelivr.net/gh/AllRates-Today/central-bank-exchange-rates@main/data/bnb/latest.json

🔗 Links

• Bulgarian National Bank rates page — live table, publication cadence, FAQ
• All central bank sources
• Package docs on the site · ERP integration guides
• API documentation · Interactive reference · Methodology
• Register (free) · Pricing
• GitHub

📜 License

MIT